Extendible towers have been well known in the art for substantial periods of time. The present invention relates to a collapsible tower that may be portable or may be permanently secured on location. Portability of such a tower is feasible only if the tower is capable of assuming a collapsed state during transportation. Likewise, for both the portable tower and the stationary tower, collapsibility of the tower greatly enhances the advantages of the tower due to ease of performing preventive maintenance and repair to the tower as well as replacement of items such as light bulbs used with apparatus secured to the top of the tower. Extendible or collapsible towers are presently existent and generally are mounted on a trailer, truck, platform or the like. Further, present extendible towers are generally employed to support banks of lights for illuminating construction sites, carnivals, fairgrounds and the like; to support signs for advertising; to support platforms that provide a work surface, and the like.
Heretofore, extendible towers have generally been constructed from welded sections and raised and lowered by various arrangements of a plurality of cables or the like. These towers are cumbersome, very expensive and represent definite safety hazards. The sections, for example, have generally been fabricated from a plurality of structural members welded together to form a skeletal structure. Skeletal structures when extended, offer less resistance to the wind than a solid structure of the same size, but are much more expensive to fabricate. Prior towers further have assumed various geometrical shapes such as triangles, circles, rectangles, etc. and, for the most part, the geometric shapes have provided edges around which guides were employed to maintain alignment between the sections. Raising and lowering of the prior art towers has normally been accomplished by a plurality of cables either interconnected between the sections as a continuous cable or as separate cables connecting each section to the next adjacent section.
Most of the presently existing towers have been found to be deficient in certain aspects. For example, structures used in the prior towers have dictated excessive expense in fabrication of the sections; set up and maintenance of the cable system; in the size and strength of the platform, trailer or the like required for transporting the tower, etc. Hence, economics precludes feasible use of existing towers for numerous situations. Further, presently existing towers may present safety hazards during raising, lowering and while standing in the raised position. Continued application of force to the cable system after the tower has been completely raised can cause the tower to buckle and fall. Likewise, during raising and lowering, certain of the presently existing towers are dangerous.
The tower of the present invention overcomes certain of the problems and disadvantages of the prior towers. Specifically, the instant tower is economical to manufacture, has a low maintenance profile, is safe, efficient and easy to operate and transport and in general is a very reliable structure.